US1836452A - Electric signal - Google Patents

Description

Dec. 15', 1931. R w. DAY 1,836,452

ELECTRI C S IGNAL Filed Jun 4, 1927 Richard W My By @MfM Attorney Patented Dec. 15, 1931 PATENT OFFICE RICHARD W. DAY, OF SEATTLE, WASHINGTON ELECTRIC SIGNAL Application filed June 4, 1927.

My present invention relates to an improved electric signal in the nature of a burglar alarm that sounds a warning when a key is inserted in the lock by an unauthorfi'ized person in an attempt to open a door, as

the front door of a house or dwelling.

The invention consists essentially in the use of an electrical conductor located within the lock casing of the door, in the path of the key that is adapted to unlock the door, and the insertion of the key in the keyhole causes the electrical conductor to complete an alarm circuit resulting in the sounding of a hell or other alarm. The electric signal circuit and alarm bell are used in connection with the usual electric bell button for ringing the house bell and a control switch is provided whereby the electric circuit for the signal or alarm may be opened or closed to render the signal inoperative or operative as desired.

In the accompanying drawings I have illustrated one complete example of the physical embodiment of my invention wherein the parts are combined and arranged according to the best mode I have thus far devised for the practical application of the principles of my invention.

Figure 1 is a view showing portions of a door and its frame equipped with the electric signal or alarm of my invention.

Figure 2 is an enlarged detail sectional view of a lock set for a front door or outer door, with the bolt locked and the alarm set.

Figure 3 is a detail sectional view of one of the circuit makers, normally closed when the door is closed.

Figure 4 is a sectional view showing the conductor in the lock casing and one of the circuit makers between the door and frame.

Figure 5 is a diagram of the wiring in connection with the conductor.

Figure 6 is a perspective view showing the key inserted in the bushing of the conductor, the latter being pushed into position to make an electrical contact when the key is shoved into the lock casing in an attempt to open the door.

In order that the general assembly and arrangement of parts may readily be understood I have indicated a door 1 and its frame Serial No. 196,594.

2 with the mortised lock-casing 3 having the usual knob-spindle 1, latch 5, bolt 6 and keeper 7, the latter having the usual hole 8 as in Figure 2 to receive the bolt 6 when the door is locked. The usual inner key hole 9 and outer key hole 10 are provided in the lock casing, and the electrical conductor 11 is located in the lock casing between these key holes. The conductor is a metallic plate disposed horizontally in the lock casing with one end 12 fixed to a fixed insulation plate 13 on the inner side of one of the walls of the lock casing 3. The conductor is fashioned of resilient metal and its free end is provided with a transversely disposed bush ing 14 having end flanges 15 and alined with the two key holes 9 and 10 in position to re ceive the key 16, or the front end 17 of its shank. Thus, when the key is inserted in the outer key hole 10, the end 17 enters the bushing 14 and continued pushing on the key pushes the bushing into the inner key hole 9, the bushing acting as a guide for the key, and the key may be turned to unlock the door in usual manner. If the electric circuit for the alarm is open, the door-key unlocks the door in usual manner, but if the electric circuit is closed, the signal is sounded.

Two pairs of circuit makers, 18 and 19 and 20 and 21, carried by the door and its frame, form part of the electric circuits for the electric house bell and alarm bell, and are nor mally closed when the door is closed. The members 19 and 21 that are secured in the door frame, or its keeper plate 7, each comprise a metal terminal lug 22 having a friction head 23 that is flush with or projects slightly from the face of the keeper. The movable members 18 and 20 carried by the door include each a casing 24, a plunger 25 movable longitudinally therein and a spring 26 for normally projecting the plunger in position so that it will frictionally engage the complementary head 23 of the fixed members 19 and 21. The casings 24 of the spring plungers are fixed in the front 27 of the lock casing 3 in position so that each plunger will engage a stationary contact point on the frame when the door is closed.

The usual bell-button or switch 28 is used to ring the house bell 29, and the burglar alarm or bell is indicated as 30, a control switch 31 being indicated for completing the circuit for either the house bell or the alarm bell by contact with points 32 and 33 respectively. In Figure 5 the switch is thrown to neutral position with both the house bell and the signal bell out of operation.

The house bell circuit includes a battery 34 and extends from button 28 through wire 35 to the circuit makers 1819, thence'by wires 36 to switch 31 and point 32, thence by wire 37 to hell 29; by wires 38 and 39 to the battery 34, and by wire 40 to the button.

The electric circuit for the alarm or signal extends from point 33 of the control switch by wire 41 to the bell 30, thence by wires 42 and 39 to battery 2%, wire 43 to plate &4 and through'the conductor 11 and wire 45 to circuit makers 2021 and wire 16 to the switch 81.

By manipulating the control switch from the neutral position of Figure 5 either the house bell circuit may be completed for use, as by -day, orthe alarm circuit may be completed for use, as at night, or during the day when the house is unoccupied, and the alarm may be located in any desired or convenient position to give a signal.

Having thus fully described my invention what I claim as new and desire to secure by Letters Patent is The combination in a circuit maker with a casing having key-holes in its opposite side walls, of a resilient conductor plate'within the casing having a fixed end and a movable free end, a cylindrical bushing mounted transversely of the free end of the plate between the holes of the side walls, and exterior flanges at the opposite ends of the bushing, whereby the bushing is adapted to receive and guide a door key from either end.

In testimony whereof I aflix my signature.

RICHARD W. DAY.

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